The present invention is related to a, preferably disposable, sanitary napkin, and provided with side wings that can be used initially or during use, according to the will and convenience of the user.
As already known in the art, sanitary napkins are normally disposable and used to collect and contain vaginal exudates, especially menstrual blood, intermenstrual secretion and even urine in cases of incontinence.
Typically, such napkins are comprised of a generally oblong body made of absorbent material, wrapped between two layers, one of which is an upper permeable layer adapted to contact the user's body, and the other is a lower impermeable layer facing her under garment.
The permeable upper layer is adapted to contact the pelvic region of the user, and therefore it is generally made of a comfortable non-irritating material. According to the current state of the art, said layer can be a perforated plastic film, a porous or crosslinked foam, a sheet of woven or non-woven material provided with natural fibers (wood or cotton fibers), synthetic fibers (polyester or polypropylene), or even of a synthetic or natural fiber combination. The upper layer can be of hydrophobic material, thus tending to remain dry.
On the other hand, the function of the impermeable lower layer is to prevent the fluid absorbed and retained in the absorbent body from passing through towards the user's clothes or skin, and it is generally a fine polyethylene sheet. The lower layer may be vapor permeable, in which case it is provided with small pores or made of a material impermeable to liquids.
Prior art sanitary napkins frequently have one or more adhesive regions in the respective impermeable lower layers, generally in a central portion in the longitudinal and/or transverse direction thereof, in order to attach the napkin to the internal face of the crutch portion of the user's panties. The adhesive region may comprise a single area or a series of discrete areas, and the trend is to apply the adhesive to the lower layer along one or more longitudinal bands, to simplify the process of manufacture.
In its turn, the absorbent body may be made of any material able to absorb and retain body exudates such as, for example, wood pulp, paper, bamboo fibers, sugar cane husks, corn stem or cob, turf moss, absorbent foams or sponges, synthetic or polymeric fibers, super-absorbent materials (that form hidrogels when in contact with liquids), combinations of the materials above, and the like.
Currently, most sanitary napkins are provided with flexible wings that extend laterally, for example, as a prolongation of one or both of the upper and lower layers, with the function of attaching the napkin to the user's panties. For such, the wings are folded around the edges of the crutch portion of the panties, and face the external surface thereof. Preferably, one or more regions of the wings are coated with adhesives, thus allowing them to be attached to the panties for preventing displacement of the napkin when in use.
The adhesive regions are preferably located over the lower surface of the wing, which is usually a prolongation of the impermeable lower layer of the napkin.
The adhesive coated regions, either in the impermeable lower layer of the napkin, or in the respective wings, must be protected against any type of contact before the napkin is used, to avoid the risk of losing their adhesive properties or inadvertent adhesion to unsuitable parts of the user's napkin or clothes, in which case the napkin might be damaged due to the softness of the materials used in its manufacture.
For that purpose, protective sheets are frequently used, which sheets are also known as "release papers" and are comprised of a sheet of paper coated with anti-adhesive resin such as silicone, or the like, thus protecting the adhesive surface until it is used, at which time they are removed for exposing the adhesive.